As the US options market heads for a sixth straight year of record volume, some best-known names in the industry are growing nervous about its over-reliance on a small group of banks to guarantee trades for the biggest market makers. Every listed US options trade goes through The Options Clearing Corp., a central counterparty that handles more than 70 million contracts a day during busy periods. The trades are submitted to the OCC by its members — who help trades get to the clearing house and act as guar ...